3+1 multijunction testing and operations platform for improved PV and TPV efficiencies

A new testing platform for semiconductor solar devices and solar concentration applications has been developed. By separating the solar radiation into two beams using a dichroic lens, simultaneous operation of a photovoltaic (PV) and a thermophotovoltaic (TPV) cell is made possible. Photons with a wavelength shorter than 1100 nm are reflected onto a PV cell; whereas the remaining solar spectrum is refracted towards a TPV cell. This testing platform takes advantage of auto-tracking and focusing capabilities using a digital mount and photoresistors. Alternative solutions to cooling problems have also been offered. Various concentration ratios, incident light intensities, acceptance angles and spot sizes can be achieved due to the versatile nature of this device. Issues with mismatching lattice constants have also been addressed through spectrum splitting. This design, when operated at its full capacity with a 3-junction PV cell and a TPV cell, allows for exciting new possibilities in high efficiency solar cell technology. These possibilities include the 3+1 hybrid multijunction cell design which could lead to higher overall efficiencies than conventional concentrators.